A former al-Shabab intelligence official, claiming the Somali militant group "basically" no longer has relations with long-time ally al-Qaida, has raised the possibility it could align itself with the Islamic State group.

Zakariya Hersi told VOA’s Somali service that if al-Shabab militants "feel they need foreign relations, since the other ties were cut, then they may seek something to replace that, something that gives them a legitimacy."

Al-Shabab has not confirmed whether it has broken ties or remains allied with al-Qaida.

A switch in allegiance would depend on the circumstances, Hersi said, adding that he does not believe any IS alliance was imminent but could occur in the next year or two.

Relationship withers

Hersi said the death of Ahmed Abdi Godane, the al-Shabab leader killed in a U.S. drone strike late last year, exposed the lack of relations between the two groups.

"Even when Godane was killed, they did not send condolences, they did not make comments," he said of al-Qaida officers.

The United States in June 2012 had offered $3 million for information leading to Hersi’s arrest. He surrendered to the Somali government last December, and the reward was withdrawn.

Concerns that al-Shabab could join the Islamic State mounted after another sub-Saharan Islamist group, Boko Haram, pledged loyalty to the self-styled caliph Abu Bakr al-Baghdadi earlier in March. That move coincided with the initial release of an official al-Shabab video by an Islamic State file-sharing site.

Other ties sanctioned

A prominent al-Shabab supporter also recently gave approval for members to join IS. Kenyan cleric Sheikh Hassan Hussein, also known as Abu Salman, said in mid-March there were no religious grounds preventing fealty to al-Baghdadi.

It's unclear if any switch of allegiances would be made by all members of al-Shabab, including the leadership, or cause a split among IS ranks, Hersi said by phone from Mogadishu.

Old-guard members of al-Shabab are believed to retain strong ties to al-Qaida. The group has forged links with nearby al-Qaida in the Arabian Peninsula, which has been less sidelined by the rise of the Islamic State than al-Qaida's central leadership.

Hersi argued such ties were never strong and were based mainly on email communications.

He added that al-Shabab, unlike either IS and al-Qaida, has limited appeal beyond its borders, with reports of foreign recruiting exaggerated. "The number of foreigners is less than 200, most of them from African countries," Hersi estimated.

Defeating the group, whether it is a proxy of al-Qaida or Islamic State, will take more than targeted killings, he said.

"It's possible that in the short term it may cause disruption or a pause, but in the longer term, attacks on individuals won't make a big impact," he said, adding "that will need a comprehensive strategy, with religious, media and political dimensions."